/* roulang page: index */
:root {
      --primary-bg: #0A0E17;
      --secondary-bg: #111620;
      --accent-cyan: #00F0FF;
      --accent-red: #FF0055;
      --text-main: #FFFFFF;
      --text-secondary: #B0B8C5;
      --text-muted: #6B7280;
      --border-dim: rgba(0,240,255,0.15);
      --border-light: rgba(255,255,255,0.06);
      --card-bg: rgba(255,255,255,0.02);
      --card-border: rgba(0,240,255,0.18);
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --shadow-glow: 0 16px 48px rgba(0,240,255,0.15);
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-input: 8px;
      --radius-container: 20px;
      --font-sans: 'Inter', 'SF Pro Text', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --transition: 0.3s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--primary-bg);
      color: var(--text-secondary);
      margin: 0;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    /* 左侧导航桌面 */
    .app-shell {
      display: flex;
      min-height: 100vh;
    }

    .side-nav {
      width: 80px;
      background: rgba(10,14,23,0.85);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border-right: 1px solid rgba(255,255,255,0.08);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 24px 0;
      position: fixed;
      left: 0;
      top: 0;
      height: 100vh;
      z-index: 1050;
      transition: width 0.3s ease;
      overflow: hidden;
    }

    .side-nav:hover {
      width: 240px;
    }

    .logo-area {
      display: flex;
      flex-direction: column;
      align-items: center;
      width: 100%;
      padding: 0 8px;
    }

    .logo-icon {
      font-size: 28px;
      color: var(--accent-cyan);
      margin-bottom: 6px;
    }

    .logo-text {
      font-weight: 700;
      font-size: 14px;
      color: white;
      white-space: nowrap;
      opacity: 0;
      transition: opacity 0.2s;
    }

    .side-nav:hover .logo-text {
      opacity: 1;
    }

    .nav-menu {
      list-style: none;
      padding: 0;
      margin: 40px 0;
      width: 100%;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    .nav-item {
      width: 100%;
      margin: 4px 0;
    }

    .nav-link {
      display: flex;
      align-items: center;
      padding: 12px 16px;
      color: var(--text-muted);
      font-size: 14px;
      border-left: 3px solid transparent;
      transition: all var(--transition);
      white-space: nowrap;
    }

    .nav-link i {
      font-size: 20px;
      width: 24px;
      text-align: center;
      margin-right: 8px;
    }

    .nav-link span {
      opacity: 0;
      transition: opacity 0.2s;
    }

    .side-nav:hover .nav-link span {
      opacity: 1;
    }

    .nav-link:hover {
      color: var(--accent-cyan);
      background: rgba(0,240,255,0.05);
      border-left: 3px solid var(--accent-cyan);
    }

    .social-icons {
      display: flex;
      flex-direction: column;
      gap: 16px;
      margin-top: auto;
    }

    .social-icons a {
      color: var(--text-muted);
      font-size: 18px;
      transition: color var(--transition);
    }

    .social-icons a:hover {
      color: var(--accent-cyan);
    }

    /* 移动端导航 */
    .mobile-nav {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: rgba(10,14,23,0.9);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
      z-index: 1040;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }

    .mobile-logo {
      font-weight: 700;
      font-size: 18px;
      color: white;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .hamburger {
      font-size: 24px;
      color: white;
      background: none;
      border: none;
    }

    .mobile-drawer {
      position: fixed;
      top: 0;
      left: -100%;
      width: 80%;
      max-width: 300px;
      height: 100vh;
      background: rgba(10,14,23,0.95);
      backdrop-filter: blur(24px);
      z-index: 1060;
      transition: left 0.3s ease;
      padding: 24px;
      display: flex;
      flex-direction: column;
    }

    .mobile-drawer.open {
      left: 0;
    }

    .drawer-close {
      align-self: flex-end;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
    }

    .drawer-nav {
      list-style: none;
      padding: 0;
      margin-top: 40px;
    }

    .drawer-nav li a {
      display: block;
      padding: 14px 0;
      font-size: 18px;
      color: var(--text-secondary);
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }

    .main-content {
      margin-left: 80px;
      flex: 1;
      width: calc(100% - 80px);
    }

    /* 容器调整 */
    .custom-container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    section {
      padding: 100px 0;
    }

    h1, h2, h3 {
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--text-main);
    }

    .btn-primary-custom {
      background: var(--accent-red);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      letter-spacing: 0.5px;
      transition: all var(--transition);
      box-shadow: 0 0 20px rgba(255,0,85,0.4);
    }

    .btn-primary-custom:hover {
      background: #FF1A6B;
      box-shadow: 0 0 28px rgba(255,0,85,0.7);
      color: white;
    }

    .btn-outline-custom {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all var(--transition);
    }

    .btn-outline-custom:hover {
      background: rgba(0,240,255,0.1);
      box-shadow: 0 0 16px rgba(0,240,255,0.5);
      color: var(--accent-cyan);
    }

    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
    }

    .glass-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-glow);
      border-color: rgba(0,240,255,0.4);
    }

    .hero-title {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 800;
    }

    .section-title {
      font-size: 36px;
      margin-bottom: 16px;
    }

    @media (max-width: 992px) {
      .side-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
      }
      section {
        padding: 60px 0;
      }
      .hero-title {
        font-size: 32px;
      }
      .section-title {
        font-size: 28px;
      }
    }